I have the faith of a Breton peasant and by the time I die I hope to have the faith of a Breton peasant's wife.

Question your priorities often, make sure God always comes first.

Preconceived ideas are like searchlights which illumine the path of the experimenter and serve him as a guide to interrogate nature. They become a danger only if he transforms them into fixed ideas-this is why I should like to see these profound words inscribed on the threshold of all the temples of science: 'The greatest derangement of the mind is to believe in something because one wishes it to be so.'

In the realm of scientific observation, luck is granted only to those who are prepared.

The greatest malfunction of spirit is to believe things.

To demonstrate experimentally that a microscopic organism actually is the cause of a disease and the agent of contagion, I know no other way, in the present state of Science, than to subject the microbe (the new and happy term introduced by M. Sédillot) to the method of cultivation out of the body.

Fortune favors the well-prepared.